The present invention relates to a steerable vehicle and, more particularly, to a capped wheel spindle assembly for such vehicle.
Towed vehicles which are towed by a towing vehicle, such as a tractor, are widely used in a number of applications, such as for example grain carts and the like in the agricultural field. These towed vehicles usually include a steering assembly at the front axle or rail of the chassis frame of the vehicle which steers the front wheels when the towing vehicle and the towed vehicle negotiate a turn.
Such steering assemblies typically include a towing assembly having a king pin which is fixed to the front axle or rail of the chassis, and a steering frame which is rotatably mounted to the king pin for rotation relative to it. The king pin may be mounted through the front rail or forward of the front rail. In either case a towing tongue may either be formed as part of the steering frame or more usually is movably mounted to the front thereof. The towing tongue has a hitch at its leading end for attachment to a hitch on the towing vehicle. The prior steering assemblies have also typically included conventional tie rods and ball joint mountings on the tie rods which are attached at one end to the steering frame and at the other end to a steering arm on the spindles upon which the steerable wheels are mounted. Thus, when the vehicle is to negotiate a turn, the steering frame rotates to the right or left about the king pin to cause the tie rods to turn the wheel spindles and wheels in one direction or the other to steer the vehicle.
The prior wheel spindles typically comprise a relatively large diameter heavy rod which has substantial strength to bear the load which is to be carried by the vehicle, and to withstand substantial forces which are exerted on the spindles particularly where the vehicle in to operate under off the road conditions and on uneven terrain as agricultural vehicles frequently do. In the prior wheel spindles, the rods usually have two portions which extend at right angles to each other. One portion extends generally horizontally to the wheel which is attached for rotation thereon, and the other portion extends vertically upwardly into a passage in a sleeve. The sleeve is welded to the end of the front chassis rail of the vehicle, whereby the spindle rotates in the sleeve passage as the vehicle is being steered. The spindle in these prior assemblies is typically held in the sleeve simply by a flat washer at the top of the sleeve and a bolt extending through the washer which is fixed to the top end of the spindle to hold the spindle in the sleeve and permit it to rotate therein.
Although such prior spindle assemblies are generally functional for their intended purpose, the simple washer construction does not seal the upper end of the sleeve against the ingress of contaminants, such as water and dirt. Thus, over a period of time, particularly where the vehicle has been parked outdoors as is typical in agricultural vehicles, water and other contaminants enter the sleeve and spindle assembly and cause rust and scoring which damage the assembly and can cause it to bind and become inoperative.
In the wheel spindle assembly of the present invention contamination of the assembly is substantially reduced, if not eliminated altogether while, at the same time, the assembly is strengthened against forces which are typically exerted on the assembly during use of the vehicle.
In one principal aspect of the present invention, a wheel spindle assembly for a steerable vehicle chassis includes a vertically extending sleeve having a cylindrical passage therein over substantially the length of the sleeve for receiving through the bottom of the sleeve a cylindrical wheel spindle for rotation in the passage. The internal surface of the sleeve in the passage defines a bearing surface for rotation of the wheel spindle relative to the surface, and a sealing closure is provided at the top of the sleeve for sealing the sleeve against the ingress of water and other contaminants through the top of the sleeve.
In another principal aspect of the present invention, the vertically extending sleeve is mounted at the end of a rail of the chassis, and a flat plate is positioned at the bottom of the sleeve which has an opening therethrough for the wheel spindle. The plate has a width greater than the cross-sectional dimension of the sleeve, and the plate is welded to the bottom of the sleeve. The plate has an opening therethrough for the wheel spindle, and the plate has a width greater than the cross-sectional dimension of the sleeve and is welded to the bottom of the sleeve and the underside of the chassis rail.
In still another principal aspect of the present invention, the sealing closure comprises a cap having an opening therethrough, and elongate fastener extending through the opening for holding the wheel spindle in the sleeve when it is journaled in the passage, and a seal for sealing the opening.
In still another principal aspect of the present invention, the last mentioned seal comprises a resilient gasket between the cap and the fastener.
In still another principal aspect of the present invention, the cap is rotatable relative to the top of the sleeve, and the fastener fixedly attaches the cap to the wheel spindle when the wheel spindle is journaled into the passage so that the cap rotates with the wheel spindle relative to the top of the sleeve.
In still another principal aspect of the present invention, the sealing closure or cap is cup-shaped having a portion which overlies the top of the sleeve and its passage, and a downturned edge about the perimeter of the overlying portion which extends downwardly from and around the top of the sleeve.
In still another principal aspect of the present invention, the downturned edge of the cap is spaced from the chassis rail, and the sleeve is welded to the chassis rail in the space.
These and other objects, features and advantages of the present invention will be more clearly understood through a consideration of the following detailed description.